Pulmonary enteric adenocarcinoma with villin brush border immunoreactivity: A case report and literature review

Pulmonary enteric adenocarcinoma, a rare histologic type of primary pulmonary adenocarcinoma with only 16 cases reported to date, has to be differentiated from metastatic colorectal carcinoma. Here we report a case of pulmonary enteric adenocarcinoma which shows villin immunoreactivity in the brush border of tumor cells. As a marker for gastrointestinal adenocarcinoma, villin has been rarely found positive like this pattern in pulmonary adenocarcinomas. This case suggests brush border immunoreactivity of villin is possible in some cases of pulmonary enteric adenocarcinomas. We suggest pathological practitioners pay attention to it.